1. Field of the Invention
The present invention relates generally to the plugging or stoppage of leaking fluids from ruptured containers. More particularly, the present invention deals with the effective sealing and repairing of hazardous or dangerous chemical fluid leaks from ruptured or fractured containers utilized for the storing, transporting and dispensing of such chemicals.
2. Description of the Prior Art
In today's highly industrialized society, tremendous quantities of chemicals are continuously being produced, stored and transported to many locations for a variety of uses and applications. Since many of these chemicals are potentially capable of creating environmental and public health hazards, it is apparent that methods and means must be implemented to safeguard the various stages of handling to which any given supply of chemical is inevitably subjected. Of particular danger are chemicals in fluid form which are normally stored and transported in plastic, glass or metallic containers. Many of these fluid chemicals are extremely hazardous if introduced into natural waterways, thereby creating environmental and public health dangers. The likelihood of accidental release to the waterways is obviously increased by the many sequences involved in the production, transferring, shipping, loading and ultimate utilization of these chemicals. Because of the great degree of handling involved, the probability of spilling such chemicals becomes very great.
Generally, the natural spilling of fluid chemicals may occur in a variety of ways. Severe spillage occurs when the container holding the chemical fluid is violently ruptured, with such rupture being accompanied by fire or explosion, thereby permitting large quantities of the fluid to be spilled out almost instantaneously. Less severe spills can result when the container maintains its integrity, but suffers enough damage to allow leakage of the hazardous fluid at a moderate rate. The leaking chemical can enter the waterways either directly, such as in the case of a barge accident or a land-based container falling into the water, or by flowing or being washed into a drainage canal or percolating into the ground water supply.
Countermeasures which neutralize or treat hazardous chemicals that are already mixed and in the waterway may require hours or days to be initiated and involve the very difficult problem of handling large volumes of water. Therefore, a vital need exists for a system which can prevent leaks of hazardous chemicals from ruptured containers by plugging or stopping the leaks emanating therefrom. Such a system should effectively function on land or under water so that a chemical container leak is securely sealed and repaired against any further leakage.
Though the prior art is replete with various methods and means for repairing ruptures and leaks in containers per se, of particular importance are the procedures and means heretofore developed for the specific plugging of leaks in damaged chemical containers. Such developments have included the utilization of rubber and plastic materials as sealing means.
The original approach of using plastic sealants or barriers that would seal leaks and prevent further disemination of the leaking chemical into a waterway was based on the use of chemical systems, such as polyurethanes, which would be forced into the hole or rupture in the container and expanded to create a seal or barrier. An example of a method utilizing this approach is that disclosed by the Patrick U.S. Pat. No. 3,772,113.
Another approach considered is the use of sealants which do not expand when forced into the hole or rupture, as in the case of the polyurethanes, but rather are already of the proper size and provide suitable adhesion to plug the leaks.
However, the former foaming approach has the advantage that the increase in volume on foaming permits a much tighter seal or barrier for the leak. The basic disadvantage of the foaming method is that the chemical reaction of the foaming may be inhibited or retarded by the chemical ingredients or fluid leaking from the container to be sealed. By contrast, the utilization of a non-expandible sealant overcomes this latter chemical reaction problem, but does not provide a very tight or secure seal.